Pump and pump control circuit apparatus and method

• US 20040009075A1
• Filed: 06/03/2003
• Published: 01/15/2004
• Est. Priority Date: 11/26/2001
• Status: Active Grant

• Current Assignee: Shurflo LLC (Pentair Plc (Ireland))
• Original Assignee: Shurflo LLC (Pentair Plc (Ireland))
• Inventors: Meza, Humberto V., Truong, Quang Minh, Gandhi, Nikhil Jitendra
• Granted Patent: US 7,083,392 B2
• Time in Patent Office: Days
• US Class Current: 417/32
• CPC Class Codes: F04B 2205/04 Pressure in the outlet chamber
• CPC Class Codes: F04B 2205/09 Flow through the pump
• CPC Class Codes: F04B 43/0054 particularities of the flexible members
• CPC Class Codes: F04B 43/04 Pumps having electric drive
• CPC Class Codes: F04B 49/065 and making use of computers

Abstract

A method and apparatus for a pump and a pump control system. The apparatus includes pistons integrally formed in a diaphragm and coupled to the diaphragm by convolutes. The convolutes have a bottom surface angled with respect to a top surface of the pistons. The apparatus also includes an outlet port positioned tangentially with respect to the perimeter of an outlet chamber. The apparatus further includes a non-mechanical pressure sensor and a temperature sensor coupled to a pump control system. For the method of the invention, the microcontroller provides a pulse-width modulation control signal to an output power stage in order to selectively control the power provided to the pump. The control signal is based on the pressure within the pump, the current being provided to the pump, the voltage level of the battery, and the temperature of the pump.

Claims

1. A pump control circuit for use with a pump, the circuit comprising:

a temperature sensor capable of producing a signal representative of changes in a temperature of the pump;

a microcontroller coupled to receive the signal from the temperature sensor, the microcontroller programmed to control a current provided to the pump; and

an output power stage coupled to receive the control signal from the microcontroller and capable of controlling the application of current to the pump in response to the control signal in order to stabilize the temperature of the pump.

2. The pump control circuit of claim 1, wherein the temperature sensor produces a signal representative of changes in the temperature inside of the pump;

and wherein the microcontroller correlates the sensed temperature to a second temperature of an outside surface of the pump and controls the current provided to the pump based on the second temperature.

3. The pump control circuit of claim 1, wherein the temperature sensor includes a semiconductor temperature sensor integrated circuit.

4. The pump control circuit of claim 1, wherein the microcontroller calculates a current limit value based on the temperature of the pump.

5. The pump control circuit of claim 4, wherein the current limit value is inversely proportional to the temperature of the pump.

6. The pump control circuit of claim 4, wherein the current limit value is approximately 5 amps when the temperature of the pump is approximately 70 degrees Fahrenheit.

7. The pump control circuit of claim 1, wherein the microcontroller controls the current provided to the pump in order to prevent the temperature of the pump from exceeding approximately 160 degrees Fahrenheit.

8. The pump control circuit of claim 1, wherein the microcontroller generates a control signal that is pulse-width modulated and has a duty cycle that is reduced in order to reduce the power supplied to the pump and that is increased in order to increase the power supplied to the pump.

9. A method of controlling a pump, the method comprising:

sensing at least one of a direct temperature of the pump and an indirect temperature of the pump;

generating a control signal based on the sensed temperature; and

controlling the application of current to the pump in response to the control signal in order to stabilize the temperature of the pump.

10. The method of claim 9, and further comprising sensing the temperature of the pump with a semiconductor temperature sensor integrated circuit.

11. The method of claim 9, and further comprising calculating a current limit value based on the sensed temperature.

12. The method of claim 11, and further comprising calculating the current limit value in inverse proportion to the sensed temperature.

13. The method of claim 11, and further comprising calculating a current limit value of approximately 5 amps when the sensed temperature is approximately 70 degrees Fahrenheit.

14. The method of claim 9, and further preventing the temperature of the pump from exceeding approximately 160 degrees Fahrenheit.

15. The method of claim 9, and further comprising sensing a first temperature inside the pump, correlating the first temperature to a second temperature of an outside surface of the pump, and generating a control signal based on the second temperature.

16. The method of claim 9, and further comprising generating a pulse-width modulation control signal based on the sensed temperature.

17. The method of claim 16, and further comprising generating a pulse-width modulation control signal having a duty cycle, reducing the duty cycle in order to reduce the power supplied to the pump, and increasing the duty cycle in order to increase the power supplied to the pump.

18. A pump control circuit for use with a pump, the circuit comprising:

an voltage source circuit designed to be coupled to a battery by a battery cable;

a microcontroller coupled to the voltage source circuit, the microcontroller programmed to estimate a length of the battery cable and to calculate a shut-off pressure value based on the length of the battery cable; and

an output power stage coupled to the microcontroller and capable of controlling the application of power to the pump based on the shut-off pressure value.

19. The pump control circuit of claim 18, wherein the microcontroller is programmed to sense the voltage of the battery and to generate a control signal if the voltage of the battery is below a high threshold and above a low threshold.

20. The pump control circuit of claim 19, wherein the battery is a standard automotive battery.

21. The pump control circuit of claim 20, wherein the high threshold is approximately 13.6 volts and the low threshold is approximately 7 volts.

22. The pump control circuit of claim 18, wherein the length of the battery cable is less than approximately 200 feet.

23. The pump control circuit of claim 18, wherein the shut-off pressure value is between approximately 38 pounds per square inch and approximately 65 pounds per square inch.

24. The pump control circuit of claim 18, wherein the microcontroller estimates the length of the battery cable by measuring a first voltage of the battery when the pump is off, by measuring a second voltage of the battery when the pump is on, and by determining a difference between the first voltage and the second voltage.

25. The pump control circuit of claim 18, wherein the microcontroller generates a pulse-width modulation control signal having a duty cycle that is reduced in order to reduce the power supplied to the pump and that is increased in order to increase the power supplied to the pump.

26. A method of controlling a pump, the method comprising:

coupling a battery cable to a battery having a voltage;

coupling the battery cable to the pump;

estimating a length of the battery cable;

calculating a shut-off pressure value based on the length of the battery cable; and

controlling the application of power to the pump based on the shut-off pressure value.

27. The method of claim 26, and further comprising coupling a standard automotive battery having a voltage of approximately 13.6 volts to the pump.

28. The method of claim 26, and further comprising sensing the voltage of the battery and generating a control signal if the sensed voltage is below a high threshold and above a low threshold.

29. The method of claim 28, and further comprising generating a control signal if the sensed voltage is below approximately 13.6 volts and above approximately 7 volts.

30. The method of claim 26, and further comprising determining the length of the battery cable as long as the battery cable is less than approximately 200 feet long.

31. The method of claim 26, and further comprising calculating a shut-off pressure value of between approximately 38 pounds per square inch and 65 pounds per square inch.

32. The method of claim 26, and further comprising estimating the length of the battery cable by measuring a first voltage of the battery when the pump is off, by measuring a second voltage of the battery when the pump is on, and by determining a difference between the first voltage and the second voltage.

33. The method of claim 26, and further comprising generating a pulse-width modulation control signal based on the shut-off pressure value.

34. The method of claim 33, and further comprising generating a pulse-width modulation control signal having a duty cycle, reducing the duty cycle in order to reduce the power supplied to the pump, and increasing the duty cycle in order to increase the power supplied to the pump.

35. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of sensing a pressure in the pump;

a microcontroller coupled to the pressure sensor, the microcontroller programmed to generate a control signal when the sensed pressure is approaching a shut-off pressure; and

an output power stage coupled to receive the control signal from the microcontroller and to provide an increased current to the pump as the sensed pressure approaches the shut-off pressure.

36. The pump control circuit of claim 35, wherein the microcontroller generates a control signal when the sensed pressure is within approximately 2 pounds per square inch of the shut-off pressure.

37. The pump control circuit of claim 35, wherein the increased current provided to the pump is increased by approximately 3 amps within approximately 2 seconds.

38. The pump control circuit of claim 35, wherein the pressure sensor produces a signal representative of changes in the pressure in an outlet chamber in the pump.

39. The pump control circuit of claim 35, wherein the pressure sensor is a silicon semiconductor pressure sensor.

40. The pump control circuit of claim 35, wherein the control signal is a pulse-width modulated control signal having a duty cycle that is increased in order to increase the current supplied to the pump.

41. The pump control circuit of claim 35, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microcontroller.

42. The pump control circuit of claim 41, wherein the amplifier and filter circuit includes a potentiometer used to calibrate the pressure sensor.

43. A method of controlling a pump, the method comprising:

sensing a pressure in the pump;

comparing the sensed pressure to a shut-off pressure value; and

increasing a current being supplied to the pump when the sensed pressure is approaching the shut-off pressure value.

44. The method of claim 43, and further comprising increasing the current being supplied to the pump when the sensed pressure is within approximately 2 pounds per square inch of the shut-off pressure value.

45. The method of claim 43, and further comprising increasing the current being provided to the pump by approximately 3 amps within approximately 2 seconds.

46. The method of claim 43, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

47. The method of claim 43, and further comprising generating a pulse-width modulation control signal based on the sensed pressure.

48. The method of claim 47, and further comprising generating a pulse-width modulation control signal having a duty cycle and increasing the duty cycle in order to increase the current supplied to the pump.

49. The method of claim 47, and further comprising amplifying and filtering the sensed pressure before generating a pulse-width modulation control signal based on the sensed pressure.

50. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of sensing a pressure in the pump; and

a microcontroller coupled to the pressure sensor and to the pump, the microcontroller operating the pump according to a high-flow mode and a low-flow mode,

the high-flow mode having a high-flow current limit value that is not dependent on the sensed pressure, and

the low-flow mode having a low-flow current limit value that is less than the high-flow current limit value and that is dependent on the sensed pressure.

51. The pump control circuit of claim 50, wherein the high-flow current limit value is approximately 10 amps.

52. The pump control circuit of claim 50, wherein the pump switches from the low-flow mode to the high-flow mode when the sensed pressure is approximately 28 pounds per square inch.

53. The pump control circuit of claim 50, wherein the pressure sensor senses the pressure in an outlet chamber in the pump.

54. The pump control circuit of claim 50, wherein the pressure sensor is a silicon semiconductor pressure sensor.

55. The pump control circuit of claim 50, wherein the microcontroller generates a pulse-width modulation control signal having a duty cycle that is reduced in order to reduce power supplied to the pump and that is increased in order to increase power supplied to the pump in response to the high-flow current limit value and the low-flow current limit value.

56. The pump control circuit of claim 50, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microcontroller.

57. The pump control circuit of claim 56, wherein the amplifier and filter circuit includes a potentiometer used to calibrate the pressure sensor.

58. A method of controlling a pump, the method comprising:

sensing a pressure in the pump; and

operating the pump in a high-flow mode and a low-flow mode based on the sensed pressure,

the high-flow mode having a high-flow current limit value that is not dependent on the sensed pressure, and

the low-flow mode having a low-flow current limit value that is less than the high-flow current limit value and that is dependent on the sensed pressure.

59. The method of claim 58, and further comprising switching the pump to a high-flow mode having a high-flow current limit value of approximately 10 amps.

60. The method of claim 58, and further comprising switching the pump from the low-flow mode to the high-flow mode when the sensed pressure is approximately 28 pounds per square inch.

61. The method of claim 58, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

62. The method of claim 58, and further comprising generating a pulse-width modulation control signal based on the sensed pressure and at least one of the high-flow current limit value and the low-flow current limit value.

63. The method of claim 62, and further comprising generating a pulse-width modulation control signal having a duty cycle, reducing the duty cycle in order to reduce power supplied to the pump, and increasing the duty cycle in order to increase power supplied to the pump.

64. The method of claim 62, and further comprising amplifying and filtering the sensed pressure before generating a pulse-width modulation control signal based on the sensed pressure.

65. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of sensing a pressure in the pump;

a microcontroller coupled to the pressure sensor and the pump,

the microcontroller programmed to generate an oscillating control signal if the sensed pressure is approaching a shut-off pressure and the pump is operating in a low-flow mode, and

the microcontroller programmed to generate a shut-off control signal if the sensed pressure is equal to or greater than the shut-off pressure and there is no flow through the pump; and

an output power stage coupled to receive the oscillating control signal and the shut-off control signal so that the output power stage provides power to the pump until flow through the pump has stopped.

66. The pump control circuit of claim 65, wherein the pressure sensor senses the pressure in an outlet chamber in the pump.

67. The pump control circuit of claim 65, wherein the pressure sensor is a silicon semiconductor pressure sensor.

68. The pump control circuit of claim 65, wherein the control signal is pulse-width modulated and has a duty cycle that is reduced in order to reduce the power supplied to the pump and that is increased in order to increase the power supplied to the pump.

69. The pump control circuit of claim 65, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microcontroller.

70. The pump control circuit of claim 69, wherein the amplifier and filter circuit includes a potentiometer used to calibrate the pressure sensor.

71. A method of controlling a pump, the method comprising:

sensing a pressure in the pump;

oscillating power to the pump when the sensed pressure is equal to or greater than a shut-off pressure and the pump is in a low-flow mode; and

shutting the pump off when the sensed pressure is greater than the shut-off pressure and there is no flow through the pump.

72. The method of claim 71, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

73. The method of claim 71, and further comprising generating a pulse-width modulation control signal based on the sensed pressure.

74. The method of claim 73, and further comprising generating a pulse-width modulation control signal having a duty cycle, reducing the duty cycle in order to reduce power supplied to the pump, and increasing the duty cycle in order to increase power supplied to the pump.

75. The method of claim 73, and further comprising amplifying and filtering the sensed pressure before generating a pulse-width modulation control signal based on the sensed pressure.

76. A method of controlling a pump, the method comprising:

sensing a pressure in the pump;

reducing power to the pump when the sensed pressure is approaching a shut-off pressure during a low-flow mode until the sensed pressure is less than the shut-off pressure; and

turning the pump off when the sensed pressure is greater than the shut-off pressure and there is no flow through the pump.

77. The method of claim 76, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

78. The method of claim 76, and further comprising generating a pulse-width modulation control signal based on the sensed pressure.

79. The method of claim 78, and further comprising generating a pulse-width modulation control signal having a duty cycle, reducing the duty cycle in order to reduce power supplied to the pump, and increasing the duty cycle in order to increase power supplied to the pump.

80. The method of claim 78, and further comprising amplifying and filtering the sensed pressure before generating a pulse-width modulation control signal based on the sensed pressure.

81. A pump control circuit for use with a pump powered by a battery having a positive terminal and a negative terminal, the circuit comprising:

a first cable designed to connect to the positive terminal of the battery;

a second cable designed to connect to the negative terminal of the battery; and

an input power stage connected to the pump,

the input power stage having a positive input connected to the first cable and a negative input connected to the second cable,

the input power stage including a power temperature control device that prevents reverse polarity damage if the first cable is connected to the negative terminal of the battery and the second cable is connected to the positive terminal of the battery.

82. The pump control circuit of claim 81, and further comprising two power temperature control devices connected in series with the positive input of the input power stage.

83. A method of controlling a pump powered by a battery having a positive terminal and a negative terminal, the method comprising:

providing an input power stage between the battery and the pump, the input power stage including a first cable connected to a positive input and a second cable connected to a negative input, the input power stage including a power temperature control device;

connecting the first cable to the negative terminal of the battery;

connecting the second cable to the positive terminal of the battery; and

preventing reverse polarity damage to the pump when the first cable is connected to the negative terminal of the battery and the second cable is connected to the positive terminal of the battery.

84. A pump diaphragm for use in a pump, the pump diaphragm comprising:

a body lying substantially in a plane, the body having a first side and a second side opposite the first side; and

a plurality of pistons integral with the first side of the body,

the plurality of pistons having distal ends substantially parallel to the plane of the body,

each one of the plurality of pistons coupled to the body via a convolute, each convolute having a side on the second side of the body lying at an angle with respect to the plane of the body.

85. The diaphragm of claim 84, wherein the plane is a first plane;

each of the plurality of pistons has a top surface lying in a second plane substantially parallel to the first plane;

the side of each convolute lies in a third plane located on the second side of the body and substantially parallel to the first and second planes; and

the third plane is at an angle with respect to the second plane.

86. The diaphragm of claim 84, wherein the convolute has a generally round shape and has an inner perimeter portion and an outer perimeter portion;

the inner perimeter portion located closer to a center of the body than the outer perimeter portion.

87. The diaphragm of claim 86, wherein the convolute has a thicker cross-section at the outer perimeter portion than the inner perimeter portion so that the side of the convolute lies at an angle sloping away from the center of the body and away from the plane of the body.

88. The diaphragm of claim 86, wherein the convolute has a greater cross-sectional width at the outer perimeter portion than the inner perimeter portion so that the side of the convolute lies at an angle sloping away from the center of the body and away from the plane of the body.

89. The diaphragm of claim 84, wherein the plurality of pistons are positioned with respect to the body portion so that the body portion is generally in the shape of a pentagon.

90. A pump comprising:

a pump housing;

at least two valves within the pump housing; and

a diaphragm having

a body generally lying in a plane,

a plurality of pistons integral with the body, a top surface of each one of the plurality of pistons lying substantially parallel to the plane of the body, and

each one of the plurality of pistons integral with the body via a convolute, a bottom surface of the convolute lying at an angle with respect to the plane of the body.

91. The pump of claim 90, wherein the top surface of each one of the plurality of pistons lies in a second plane above the body, wherein the bottom surface of the convolute is lying in a third plane below the body, and wherein the third plane is at an angle with respect to the second plane.

92. The pump of claim 90, wherein the convolute has an inner perimeter portion and an outer perimeter portion;

the inner perimeter portion is closer to a center point of the body portion than the outer perimeter portion; and

the convolute is deeper at the outer perimeter portion than the inner perimeter portion so that the bottom surface of the convolute lies at an angle sloping away from the center point of the body portion and away from the plane of the body portion toward the rear housing.

93. The pump of claim 90, wherein the convolute is integral with the pistons and with the body.

94. The pump of claim 90, further comprising five chambers within which are located five valves, wherein the plurality of pistons includes five pistons.

95. The pump of claim 94, wherein the plurality of pistons are positioned so that the body portion is generally in the shape of a pentagon.

96. A pump control circuit for use with a pump, the circuit comprising:

an electronic pressure sensor that senses actual changes in pressure inside the pump and generates a signal representing the sensed pressure;

a microcontroller coupled to receive the signal from the pressure sensor, the microcontroller programmed to control the speed of the pump based on the sensed pressure by generating a pulse-width modulation control signal; and

an output power stage coupled to receive the control signal from the microcontroller and capable of controlling the application of power to the pump in response to the control signal.

97. The pump control circuit of claim 96, wherein the pressure sensor produces a signal representative of changes in the pressure in an outlet chamber in the pump.

98. The pump control circuit of claim 96, wherein the pulse-width modulation control signal has a duty cycle that is reduced in order to reduce the power supplied to the pump and that is increased in order to increase the power supplied to the pump.

99. The pump control circuit of claim 96, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microprocessor.

100. The pump control circuit of claim 96, wherein the output power stage includes a comparator circuit which determines whether the control signal is a high control signal or a low control signal, and wherein an output of the comparator circuit is positive for a high control signal and negative for a low control signal.

101. A method of controlling a pump, the method comprising:

sensing an actual pressure inside the pump with an electronic pressure sensor;

generating a pulse-width modulation control signal based on the sensed pressure; and

controlling the application of power to the pump in response to the control signal.

102. The method of claim 101, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

103. The method of claim 101, wherein generating a pulse-width modulation control signal based on the sensed pressure includes generating a pulse-width modulation control signal having a duty cycle, and further comprising reducing the duty cycle in order to reduce the power supplied to the pump and increasing the duty cycle in order to increase the power supplied to the pump.

104. The method of claim 101, and further comprising amplifying and filtering the sensed pressure before generating a pulse-width modulation control signal based on the sensed pressure.

105. A pump control circuit for use with a pump, the circuit comprising:

an electronic pressure sensor capable of sensing an actual pressure inside the pump;

a current sensing circuit capable of sensing a current being provided to the pump;

a microcontroller coupled to the pressure sensor and the current sensing circuit,

the microcontroller programmed to determine a current limit threshold based on the sensed pressure, and

the microcontroller programmed to generate a high control signal if the sensed current is less than the current limit threshold and a low control signal if the sensed current is greater than the current limit threshold; and

an output power stage coupled to receive the control signal from the microcontroller so that if the control signal is a low control signal the power provided to the pump is reduced until the sensed current is less than the current limit threshold.

106. The pump control circuit of claim 105, wherein the pressure sensor is capable of sensing the pressure in an outlet chamber in the pump.

107. The pump control circuit of claim 105, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microprocessor.

108. The pump control circuit of claim 105, wherein the output power stage includes a comparator circuit which determines whether the control signal is a high control signal or a low control signal, and wherein an output of the comparator circuit is positive for a high control signal and negative for a low control signal.

109. A method of controlling a pump, the method comprising:

sensing a pressure in the pump;

determining a current limit threshold based on the sensed pressure;

sensing a current being provided to the pump;

comparing the sensed current to the current limit threshold; and

providing power to the pump if the sensed current is less than the current limit threshold and reducing the power provided to the pump if the sensed current is greater than the current limit threshold until the sensed current is less than the current limit threshold.